Lining elements are used for repairing pipes, in particular main pipes, branch pipes and house connection lines in the area of the sewerage system, and also in the area of buildings. By introducing the lining elements, leaking pipe sections, in particular of pipe joint sections, can be repaired. The lining element is provided with an adhesive glue for durable bonding with the interior of the tube wall, wherein, in particular, a hardenable resin is used. Typically, the lining element comprises a layer of resin-absorbing material, in particular a non-woven, or fibrous material. Prior to insertion of the lining element, the latter is impregnated with the resin, and then the lining element is brought into its final position at the area to be repaired. Usually, the well-known inversion methods are used. After the resin has hardened, the lining element is in positive and frictional engagement with the inner tube wall. This approach is often necessary at pipe junctions where two pipes meet.
For the manufacture of the lining element it is known from US 2008/0078463 A1 that the branch tube section of a hat-shaped lining element is rolled from an initially planar portion to a tube-like shape, and then the facing side edges are sewn together. Subsequently, the seam can be covered by a masking tape. A similar approach is known from U.S. Pat. No. 5,915,419, where the tube-like section provided for lining the branch pipe is provided by rolling it and connecting the facing edges by means of a seam. Subsequently, a rim is connected to this tube-like section by means of an adhesive bond.
In this manufacturing method, it is a proven drawback that the branch pipe section and the main pipe section of the lining element must be connected by an annular seam. The creation of such a radial seam is very complex and requires sewing along a circular path.